sd.c revision 776b23a0363d99ca402edc1aba1db8099b747b33
1/* 2 * sd.c Copyright (C) 1992 Drew Eckhardt 3 * Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale 4 * 5 * Linux scsi disk driver 6 * Initial versions: Drew Eckhardt 7 * Subsequent revisions: Eric Youngdale 8 * Modification history: 9 * - Drew Eckhardt <drew@colorado.edu> original 10 * - Eric Youngdale <eric@andante.org> add scatter-gather, multiple 11 * outstanding request, and other enhancements. 12 * Support loadable low-level scsi drivers. 13 * - Jirka Hanika <geo@ff.cuni.cz> support more scsi disks using 14 * eight major numbers. 15 * - Richard Gooch <rgooch@atnf.csiro.au> support devfs. 16 * - Torben Mathiasen <tmm@image.dk> Resource allocation fixes in 17 * sd_init and cleanups. 18 * - Alex Davis <letmein@erols.com> Fix problem where partition info 19 * not being read in sd_open. Fix problem where removable media 20 * could be ejected after sd_open. 21 * - Douglas Gilbert <dgilbert@interlog.com> cleanup for lk 2.5.x 22 * - Badari Pulavarty <pbadari@us.ibm.com>, Matthew Wilcox 23 * <willy@debian.org>, Kurt Garloff <garloff@suse.de>: 24 * Support 32k/1M disks. 25 * 26 * Logging policy (needs CONFIG_SCSI_LOGGING defined): 27 * - setting up transfer: SCSI_LOG_HLQUEUE levels 1 and 2 28 * - end of transfer (bh + scsi_lib): SCSI_LOG_HLCOMPLETE level 1 29 * - entering sd_ioctl: SCSI_LOG_IOCTL level 1 30 * - entering other commands: SCSI_LOG_HLQUEUE level 3 31 * Note: when the logging level is set by the user, it must be greater 32 * than the level indicated above to trigger output. 33 */ 34 35#include <linux/config.h> 36#include <linux/module.h> 37#include <linux/fs.h> 38#include <linux/kernel.h> 39#include <linux/sched.h> 40#include <linux/mm.h> 41#include <linux/bio.h> 42#include <linux/genhd.h> 43#include <linux/hdreg.h> 44#include <linux/errno.h> 45#include <linux/idr.h> 46#include <linux/interrupt.h> 47#include <linux/init.h> 48#include <linux/blkdev.h> 49#include <linux/blkpg.h> 50#include <linux/kref.h> 51#include <linux/delay.h> 52#include <linux/mutex.h> 53#include <asm/uaccess.h> 54 55#include <scsi/scsi.h> 56#include <scsi/scsi_cmnd.h> 57#include <scsi/scsi_dbg.h> 58#include <scsi/scsi_device.h> 59#include <scsi/scsi_driver.h> 60#include <scsi/scsi_eh.h> 61#include <scsi/scsi_host.h> 62#include <scsi/scsi_ioctl.h> 63#include <scsi/scsicam.h> 64 65#include "scsi_logging.h" 66 67/* 68 * More than enough for everybody ;) The huge number of majors 69 * is a leftover from 16bit dev_t days, we don't really need that 70 * much numberspace. 71 */ 72#define SD_MAJORS 16 73 74/* 75 * This is limited by the naming scheme enforced in sd_probe, 76 * add another character to it if you really need more disks. 77 */ 78#define SD_MAX_DISKS (((26 * 26) + 26 + 1) * 26) 79 80/* 81 * Time out in seconds for disks and Magneto-opticals (which are slower). 82 */ 83#define SD_TIMEOUT (30 * HZ) 84#define SD_MOD_TIMEOUT (75 * HZ) 85 86/* 87 * Number of allowed retries 88 */ 89#define SD_MAX_RETRIES 5 90#define SD_PASSTHROUGH_RETRIES 1 91 92static void scsi_disk_release(struct kref *kref); 93 94struct scsi_disk { 95 struct scsi_driver *driver; /* always &sd_template */ 96 struct scsi_device *device; 97 struct kref kref; 98 struct gendisk *disk; 99 unsigned int openers; /* protected by BKL for now, yuck */ 100 sector_t capacity; /* size in 512-byte sectors */ 101 u32 index; 102 u8 media_present; 103 u8 write_prot; 104 unsigned WCE : 1; /* state of disk WCE bit */ 105 unsigned RCD : 1; /* state of disk RCD bit, unused */ 106 unsigned DPOFUA : 1; /* state of disk DPOFUA bit */ 107}; 108 109static DEFINE_IDR(sd_index_idr); 110static DEFINE_SPINLOCK(sd_index_lock); 111 112/* This semaphore is used to mediate the 0->1 reference get in the 113 * face of object destruction (i.e. we can't allow a get on an 114 * object after last put) */ 115static DEFINE_MUTEX(sd_ref_mutex); 116 117static int sd_revalidate_disk(struct gendisk *disk); 118static void sd_rw_intr(struct scsi_cmnd * SCpnt); 119 120static int sd_probe(struct device *); 121static int sd_remove(struct device *); 122static void sd_shutdown(struct device *dev); 123static void sd_rescan(struct device *); 124static int sd_init_command(struct scsi_cmnd *); 125static int sd_issue_flush(struct device *, sector_t *); 126static void sd_prepare_flush(request_queue_t *, struct request *); 127static void sd_read_capacity(struct scsi_disk *sdkp, char *diskname, 128 unsigned char *buffer); 129 130static struct scsi_driver sd_template = { 131 .owner = THIS_MODULE, 132 .gendrv = { 133 .name = "sd", 134 .probe = sd_probe, 135 .remove = sd_remove, 136 .shutdown = sd_shutdown, 137 }, 138 .rescan = sd_rescan, 139 .init_command = sd_init_command, 140 .issue_flush = sd_issue_flush, 141}; 142 143/* 144 * Device no to disk mapping: 145 * 146 * major disc2 disc p1 147 * |............|.............|....|....| <- dev_t 148 * 31 20 19 8 7 4 3 0 149 * 150 * Inside a major, we have 16k disks, however mapped non- 151 * contiguously. The first 16 disks are for major0, the next 152 * ones with major1, ... Disk 256 is for major0 again, disk 272 153 * for major1, ... 154 * As we stay compatible with our numbering scheme, we can reuse 155 * the well-know SCSI majors 8, 65--71, 136--143. 156 */ 157static int sd_major(int major_idx) 158{ 159 switch (major_idx) { 160 case 0: 161 return SCSI_DISK0_MAJOR; 162 case 1 ... 7: 163 return SCSI_DISK1_MAJOR + major_idx - 1; 164 case 8 ... 15: 165 return SCSI_DISK8_MAJOR + major_idx - 8; 166 default: 167 BUG(); 168 return 0; /* shut up gcc */ 169 } 170} 171 172#define to_scsi_disk(obj) container_of(obj,struct scsi_disk,kref) 173 174static inline struct scsi_disk *scsi_disk(struct gendisk *disk) 175{ 176 return container_of(disk->private_data, struct scsi_disk, driver); 177} 178 179static struct scsi_disk *__scsi_disk_get(struct gendisk *disk) 180{ 181 struct scsi_disk *sdkp = NULL; 182 183 if (disk->private_data) { 184 sdkp = scsi_disk(disk); 185 if (scsi_device_get(sdkp->device) == 0) 186 kref_get(&sdkp->kref); 187 else 188 sdkp = NULL; 189 } 190 return sdkp; 191} 192 193static struct scsi_disk *scsi_disk_get(struct gendisk *disk) 194{ 195 struct scsi_disk *sdkp; 196 197 mutex_lock(&sd_ref_mutex); 198 sdkp = __scsi_disk_get(disk); 199 mutex_unlock(&sd_ref_mutex); 200 return sdkp; 201} 202 203static struct scsi_disk *scsi_disk_get_from_dev(struct device *dev) 204{ 205 struct scsi_disk *sdkp; 206 207 mutex_lock(&sd_ref_mutex); 208 sdkp = dev_get_drvdata(dev); 209 if (sdkp) 210 sdkp = __scsi_disk_get(sdkp->disk); 211 mutex_unlock(&sd_ref_mutex); 212 return sdkp; 213} 214 215static void scsi_disk_put(struct scsi_disk *sdkp) 216{ 217 struct scsi_device *sdev = sdkp->device; 218 219 mutex_lock(&sd_ref_mutex); 220 kref_put(&sdkp->kref, scsi_disk_release); 221 scsi_device_put(sdev); 222 mutex_unlock(&sd_ref_mutex); 223} 224 225/** 226 * sd_init_command - build a scsi (read or write) command from 227 * information in the request structure. 228 * @SCpnt: pointer to mid-level's per scsi command structure that 229 * contains request and into which the scsi command is written 230 * 231 * Returns 1 if successful and 0 if error (or cannot be done now). 232 **/ 233static int sd_init_command(struct scsi_cmnd * SCpnt) 234{ 235 struct scsi_device *sdp = SCpnt->device; 236 struct request *rq = SCpnt->request; 237 struct gendisk *disk = rq->rq_disk; 238 sector_t block = rq->sector; 239 unsigned int this_count = SCpnt->request_bufflen >> 9; 240 unsigned int timeout = sdp->timeout; 241 242 SCSI_LOG_HLQUEUE(1, printk("sd_init_command: disk=%s, block=%llu, " 243 "count=%d\n", disk->disk_name, 244 (unsigned long long)block, this_count)); 245 246 if (!sdp || !scsi_device_online(sdp) || 247 block + rq->nr_sectors > get_capacity(disk)) { 248 SCSI_LOG_HLQUEUE(2, printk("Finishing %ld sectors\n", 249 rq->nr_sectors)); 250 SCSI_LOG_HLQUEUE(2, printk("Retry with 0x%p\n", SCpnt)); 251 return 0; 252 } 253 254 if (sdp->changed) { 255 /* 256 * quietly refuse to do anything to a changed disc until 257 * the changed bit has been reset 258 */ 259 /* printk("SCSI disk has been changed. Prohibiting further I/O.\n"); */ 260 return 0; 261 } 262 SCSI_LOG_HLQUEUE(2, printk("%s : block=%llu\n", 263 disk->disk_name, (unsigned long long)block)); 264 265 /* 266 * If we have a 1K hardware sectorsize, prevent access to single 267 * 512 byte sectors. In theory we could handle this - in fact 268 * the scsi cdrom driver must be able to handle this because 269 * we typically use 1K blocksizes, and cdroms typically have 270 * 2K hardware sectorsizes. Of course, things are simpler 271 * with the cdrom, since it is read-only. For performance 272 * reasons, the filesystems should be able to handle this 273 * and not force the scsi disk driver to use bounce buffers 274 * for this. 275 */ 276 if (sdp->sector_size == 1024) { 277 if ((block & 1) || (rq->nr_sectors & 1)) { 278 printk(KERN_ERR "sd: Bad block number requested"); 279 return 0; 280 } else { 281 block = block >> 1; 282 this_count = this_count >> 1; 283 } 284 } 285 if (sdp->sector_size == 2048) { 286 if ((block & 3) || (rq->nr_sectors & 3)) { 287 printk(KERN_ERR "sd: Bad block number requested"); 288 return 0; 289 } else { 290 block = block >> 2; 291 this_count = this_count >> 2; 292 } 293 } 294 if (sdp->sector_size == 4096) { 295 if ((block & 7) || (rq->nr_sectors & 7)) { 296 printk(KERN_ERR "sd: Bad block number requested"); 297 return 0; 298 } else { 299 block = block >> 3; 300 this_count = this_count >> 3; 301 } 302 } 303 if (rq_data_dir(rq) == WRITE) { 304 if (!sdp->writeable) { 305 return 0; 306 } 307 SCpnt->cmnd[0] = WRITE_6; 308 SCpnt->sc_data_direction = DMA_TO_DEVICE; 309 } else if (rq_data_dir(rq) == READ) { 310 SCpnt->cmnd[0] = READ_6; 311 SCpnt->sc_data_direction = DMA_FROM_DEVICE; 312 } else { 313 printk(KERN_ERR "sd: Unknown command %lx\n", rq->flags); 314/* overkill panic("Unknown sd command %lx\n", rq->flags); */ 315 return 0; 316 } 317 318 SCSI_LOG_HLQUEUE(2, printk("%s : %s %d/%ld 512 byte blocks.\n", 319 disk->disk_name, (rq_data_dir(rq) == WRITE) ? 320 "writing" : "reading", this_count, rq->nr_sectors)); 321 322 SCpnt->cmnd[1] = 0; 323 324 if (block > 0xffffffff) { 325 SCpnt->cmnd[0] += READ_16 - READ_6; 326 SCpnt->cmnd[1] |= blk_fua_rq(rq) ? 0x8 : 0; 327 SCpnt->cmnd[2] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0; 328 SCpnt->cmnd[3] = sizeof(block) > 4 ? (unsigned char) (block >> 48) & 0xff : 0; 329 SCpnt->cmnd[4] = sizeof(block) > 4 ? (unsigned char) (block >> 40) & 0xff : 0; 330 SCpnt->cmnd[5] = sizeof(block) > 4 ? (unsigned char) (block >> 32) & 0xff : 0; 331 SCpnt->cmnd[6] = (unsigned char) (block >> 24) & 0xff; 332 SCpnt->cmnd[7] = (unsigned char) (block >> 16) & 0xff; 333 SCpnt->cmnd[8] = (unsigned char) (block >> 8) & 0xff; 334 SCpnt->cmnd[9] = (unsigned char) block & 0xff; 335 SCpnt->cmnd[10] = (unsigned char) (this_count >> 24) & 0xff; 336 SCpnt->cmnd[11] = (unsigned char) (this_count >> 16) & 0xff; 337 SCpnt->cmnd[12] = (unsigned char) (this_count >> 8) & 0xff; 338 SCpnt->cmnd[13] = (unsigned char) this_count & 0xff; 339 SCpnt->cmnd[14] = SCpnt->cmnd[15] = 0; 340 } else if ((this_count > 0xff) || (block > 0x1fffff) || 341 SCpnt->device->use_10_for_rw) { 342 if (this_count > 0xffff) 343 this_count = 0xffff; 344 345 SCpnt->cmnd[0] += READ_10 - READ_6; 346 SCpnt->cmnd[1] |= blk_fua_rq(rq) ? 0x8 : 0; 347 SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff; 348 SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff; 349 SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff; 350 SCpnt->cmnd[5] = (unsigned char) block & 0xff; 351 SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0; 352 SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff; 353 SCpnt->cmnd[8] = (unsigned char) this_count & 0xff; 354 } else { 355 if (unlikely(blk_fua_rq(rq))) { 356 /* 357 * This happens only if this drive failed 358 * 10byte rw command with ILLEGAL_REQUEST 359 * during operation and thus turned off 360 * use_10_for_rw. 361 */ 362 printk(KERN_ERR "sd: FUA write on READ/WRITE(6) drive\n"); 363 return 0; 364 } 365 366 SCpnt->cmnd[1] |= (unsigned char) ((block >> 16) & 0x1f); 367 SCpnt->cmnd[2] = (unsigned char) ((block >> 8) & 0xff); 368 SCpnt->cmnd[3] = (unsigned char) block & 0xff; 369 SCpnt->cmnd[4] = (unsigned char) this_count; 370 SCpnt->cmnd[5] = 0; 371 } 372 SCpnt->request_bufflen = SCpnt->bufflen = 373 this_count * sdp->sector_size; 374 375 /* 376 * We shouldn't disconnect in the middle of a sector, so with a dumb 377 * host adapter, it's safe to assume that we can at least transfer 378 * this many bytes between each connect / disconnect. 379 */ 380 SCpnt->transfersize = sdp->sector_size; 381 SCpnt->underflow = this_count << 9; 382 SCpnt->allowed = SD_MAX_RETRIES; 383 SCpnt->timeout_per_command = timeout; 384 385 /* 386 * This is the completion routine we use. This is matched in terms 387 * of capability to this function. 388 */ 389 SCpnt->done = sd_rw_intr; 390 391 /* 392 * This indicates that the command is ready from our end to be 393 * queued. 394 */ 395 return 1; 396} 397 398/** 399 * sd_open - open a scsi disk device 400 * @inode: only i_rdev member may be used 401 * @filp: only f_mode and f_flags may be used 402 * 403 * Returns 0 if successful. Returns a negated errno value in case 404 * of error. 405 * 406 * Note: This can be called from a user context (e.g. fsck(1) ) 407 * or from within the kernel (e.g. as a result of a mount(1) ). 408 * In the latter case @inode and @filp carry an abridged amount 409 * of information as noted above. 410 **/ 411static int sd_open(struct inode *inode, struct file *filp) 412{ 413 struct gendisk *disk = inode->i_bdev->bd_disk; 414 struct scsi_disk *sdkp; 415 struct scsi_device *sdev; 416 int retval; 417 418 if (!(sdkp = scsi_disk_get(disk))) 419 return -ENXIO; 420 421 422 SCSI_LOG_HLQUEUE(3, printk("sd_open: disk=%s\n", disk->disk_name)); 423 424 sdev = sdkp->device; 425 426 /* 427 * If the device is in error recovery, wait until it is done. 428 * If the device is offline, then disallow any access to it. 429 */ 430 retval = -ENXIO; 431 if (!scsi_block_when_processing_errors(sdev)) 432 goto error_out; 433 434 if (sdev->removable || sdkp->write_prot) 435 check_disk_change(inode->i_bdev); 436 437 /* 438 * If the drive is empty, just let the open fail. 439 */ 440 retval = -ENOMEDIUM; 441 if (sdev->removable && !sdkp->media_present && 442 !(filp->f_flags & O_NDELAY)) 443 goto error_out; 444 445 /* 446 * If the device has the write protect tab set, have the open fail 447 * if the user expects to be able to write to the thing. 448 */ 449 retval = -EROFS; 450 if (sdkp->write_prot && (filp->f_mode & FMODE_WRITE)) 451 goto error_out; 452 453 /* 454 * It is possible that the disk changing stuff resulted in 455 * the device being taken offline. If this is the case, 456 * report this to the user, and don't pretend that the 457 * open actually succeeded. 458 */ 459 retval = -ENXIO; 460 if (!scsi_device_online(sdev)) 461 goto error_out; 462 463 if (!sdkp->openers++ && sdev->removable) { 464 if (scsi_block_when_processing_errors(sdev)) 465 scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT); 466 } 467 468 return 0; 469 470error_out: 471 scsi_disk_put(sdkp); 472 return retval; 473} 474 475/** 476 * sd_release - invoked when the (last) close(2) is called on this 477 * scsi disk. 478 * @inode: only i_rdev member may be used 479 * @filp: only f_mode and f_flags may be used 480 * 481 * Returns 0. 482 * 483 * Note: may block (uninterruptible) if error recovery is underway 484 * on this disk. 485 **/ 486static int sd_release(struct inode *inode, struct file *filp) 487{ 488 struct gendisk *disk = inode->i_bdev->bd_disk; 489 struct scsi_disk *sdkp = scsi_disk(disk); 490 struct scsi_device *sdev = sdkp->device; 491 492 SCSI_LOG_HLQUEUE(3, printk("sd_release: disk=%s\n", disk->disk_name)); 493 494 if (!--sdkp->openers && sdev->removable) { 495 if (scsi_block_when_processing_errors(sdev)) 496 scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW); 497 } 498 499 /* 500 * XXX and what if there are packets in flight and this close() 501 * XXX is followed by a "rmmod sd_mod"? 502 */ 503 scsi_disk_put(sdkp); 504 return 0; 505} 506 507static int sd_getgeo(struct block_device *bdev, struct hd_geometry *geo) 508{ 509 struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk); 510 struct scsi_device *sdp = sdkp->device; 511 struct Scsi_Host *host = sdp->host; 512 int diskinfo[4]; 513 514 /* default to most commonly used values */ 515 diskinfo[0] = 0x40; /* 1 << 6 */ 516 diskinfo[1] = 0x20; /* 1 << 5 */ 517 diskinfo[2] = sdkp->capacity >> 11; 518 519 /* override with calculated, extended default, or driver values */ 520 if (host->hostt->bios_param) 521 host->hostt->bios_param(sdp, bdev, sdkp->capacity, diskinfo); 522 else 523 scsicam_bios_param(bdev, sdkp->capacity, diskinfo); 524 525 geo->heads = diskinfo[0]; 526 geo->sectors = diskinfo[1]; 527 geo->cylinders = diskinfo[2]; 528 return 0; 529} 530 531/** 532 * sd_ioctl - process an ioctl 533 * @inode: only i_rdev/i_bdev members may be used 534 * @filp: only f_mode and f_flags may be used 535 * @cmd: ioctl command number 536 * @arg: this is third argument given to ioctl(2) system call. 537 * Often contains a pointer. 538 * 539 * Returns 0 if successful (some ioctls return postive numbers on 540 * success as well). Returns a negated errno value in case of error. 541 * 542 * Note: most ioctls are forward onto the block subsystem or further 543 * down in the scsi subsytem. 544 **/ 545static int sd_ioctl(struct inode * inode, struct file * filp, 546 unsigned int cmd, unsigned long arg) 547{ 548 struct block_device *bdev = inode->i_bdev; 549 struct gendisk *disk = bdev->bd_disk; 550 struct scsi_device *sdp = scsi_disk(disk)->device; 551 void __user *p = (void __user *)arg; 552 int error; 553 554 SCSI_LOG_IOCTL(1, printk("sd_ioctl: disk=%s, cmd=0x%x\n", 555 disk->disk_name, cmd)); 556 557 /* 558 * If we are in the middle of error recovery, don't let anyone 559 * else try and use this device. Also, if error recovery fails, it 560 * may try and take the device offline, in which case all further 561 * access to the device is prohibited. 562 */ 563 error = scsi_nonblockable_ioctl(sdp, cmd, p, filp); 564 if (!scsi_block_when_processing_errors(sdp) || !error) 565 return error; 566 567 /* 568 * Send SCSI addressing ioctls directly to mid level, send other 569 * ioctls to block level and then onto mid level if they can't be 570 * resolved. 571 */ 572 switch (cmd) { 573 case SCSI_IOCTL_GET_IDLUN: 574 case SCSI_IOCTL_GET_BUS_NUMBER: 575 return scsi_ioctl(sdp, cmd, p); 576 default: 577 error = scsi_cmd_ioctl(filp, disk, cmd, p); 578 if (error != -ENOTTY) 579 return error; 580 } 581 return scsi_ioctl(sdp, cmd, p); 582} 583 584static void set_media_not_present(struct scsi_disk *sdkp) 585{ 586 sdkp->media_present = 0; 587 sdkp->capacity = 0; 588 sdkp->device->changed = 1; 589} 590 591/** 592 * sd_media_changed - check if our medium changed 593 * @disk: kernel device descriptor 594 * 595 * Returns 0 if not applicable or no change; 1 if change 596 * 597 * Note: this function is invoked from the block subsystem. 598 **/ 599static int sd_media_changed(struct gendisk *disk) 600{ 601 struct scsi_disk *sdkp = scsi_disk(disk); 602 struct scsi_device *sdp = sdkp->device; 603 int retval; 604 605 SCSI_LOG_HLQUEUE(3, printk("sd_media_changed: disk=%s\n", 606 disk->disk_name)); 607 608 if (!sdp->removable) 609 return 0; 610 611 /* 612 * If the device is offline, don't send any commands - just pretend as 613 * if the command failed. If the device ever comes back online, we 614 * can deal with it then. It is only because of unrecoverable errors 615 * that we would ever take a device offline in the first place. 616 */ 617 if (!scsi_device_online(sdp)) 618 goto not_present; 619 620 /* 621 * Using TEST_UNIT_READY enables differentiation between drive with 622 * no cartridge loaded - NOT READY, drive with changed cartridge - 623 * UNIT ATTENTION, or with same cartridge - GOOD STATUS. 624 * 625 * Drives that auto spin down. eg iomega jaz 1G, will be started 626 * by sd_spinup_disk() from sd_revalidate_disk(), which happens whenever 627 * sd_revalidate() is called. 628 */ 629 retval = -ENODEV; 630 if (scsi_block_when_processing_errors(sdp)) 631 retval = scsi_test_unit_ready(sdp, SD_TIMEOUT, SD_MAX_RETRIES); 632 633 /* 634 * Unable to test, unit probably not ready. This usually 635 * means there is no disc in the drive. Mark as changed, 636 * and we will figure it out later once the drive is 637 * available again. 638 */ 639 if (retval) 640 goto not_present; 641 642 /* 643 * For removable scsi disk we have to recognise the presence 644 * of a disk in the drive. This is kept in the struct scsi_disk 645 * struct and tested at open ! Daniel Roche (dan@lectra.fr) 646 */ 647 sdkp->media_present = 1; 648 649 retval = sdp->changed; 650 sdp->changed = 0; 651 652 return retval; 653 654not_present: 655 set_media_not_present(sdkp); 656 return 1; 657} 658 659static int sd_sync_cache(struct scsi_device *sdp) 660{ 661 int retries, res; 662 struct scsi_sense_hdr sshdr; 663 664 if (!scsi_device_online(sdp)) 665 return -ENODEV; 666 667 668 for (retries = 3; retries > 0; --retries) { 669 unsigned char cmd[10] = { 0 }; 670 671 cmd[0] = SYNCHRONIZE_CACHE; 672 /* 673 * Leave the rest of the command zero to indicate 674 * flush everything. 675 */ 676 res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr, 677 SD_TIMEOUT, SD_MAX_RETRIES); 678 if (res == 0) 679 break; 680 } 681 682 if (res) { printk(KERN_WARNING "FAILED\n status = %x, message = %02x, " 683 "host = %d, driver = %02x\n ", 684 status_byte(res), msg_byte(res), 685 host_byte(res), driver_byte(res)); 686 if (driver_byte(res) & DRIVER_SENSE) 687 scsi_print_sense_hdr("sd", &sshdr); 688 } 689 690 return res; 691} 692 693static int sd_issue_flush(struct device *dev, sector_t *error_sector) 694{ 695 int ret = 0; 696 struct scsi_device *sdp = to_scsi_device(dev); 697 struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev); 698 699 if (!sdkp) 700 return -ENODEV; 701 702 if (sdkp->WCE) 703 ret = sd_sync_cache(sdp); 704 scsi_disk_put(sdkp); 705 return ret; 706} 707 708static void sd_prepare_flush(request_queue_t *q, struct request *rq) 709{ 710 memset(rq->cmd, 0, sizeof(rq->cmd)); 711 rq->flags |= REQ_BLOCK_PC; 712 rq->timeout = SD_TIMEOUT; 713 rq->cmd[0] = SYNCHRONIZE_CACHE; 714 rq->cmd_len = 10; 715} 716 717static void sd_rescan(struct device *dev) 718{ 719 struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev); 720 721 if (sdkp) { 722 sd_revalidate_disk(sdkp->disk); 723 scsi_disk_put(sdkp); 724 } 725} 726 727 728#ifdef CONFIG_COMPAT 729/* 730 * This gets directly called from VFS. When the ioctl 731 * is not recognized we go back to the other translation paths. 732 */ 733static long sd_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 734{ 735 struct block_device *bdev = file->f_dentry->d_inode->i_bdev; 736 struct gendisk *disk = bdev->bd_disk; 737 struct scsi_device *sdev = scsi_disk(disk)->device; 738 739 /* 740 * If we are in the middle of error recovery, don't let anyone 741 * else try and use this device. Also, if error recovery fails, it 742 * may try and take the device offline, in which case all further 743 * access to the device is prohibited. 744 */ 745 if (!scsi_block_when_processing_errors(sdev)) 746 return -ENODEV; 747 748 if (sdev->host->hostt->compat_ioctl) { 749 int ret; 750 751 ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg); 752 753 return ret; 754 } 755 756 /* 757 * Let the static ioctl translation table take care of it. 758 */ 759 return -ENOIOCTLCMD; 760} 761#endif 762 763static struct block_device_operations sd_fops = { 764 .owner = THIS_MODULE, 765 .open = sd_open, 766 .release = sd_release, 767 .ioctl = sd_ioctl, 768 .getgeo = sd_getgeo, 769#ifdef CONFIG_COMPAT 770 .compat_ioctl = sd_compat_ioctl, 771#endif 772 .media_changed = sd_media_changed, 773 .revalidate_disk = sd_revalidate_disk, 774}; 775 776/** 777 * sd_rw_intr - bottom half handler: called when the lower level 778 * driver has completed (successfully or otherwise) a scsi command. 779 * @SCpnt: mid-level's per command structure. 780 * 781 * Note: potentially run from within an ISR. Must not block. 782 **/ 783static void sd_rw_intr(struct scsi_cmnd * SCpnt) 784{ 785 int result = SCpnt->result; 786 int this_count = SCpnt->bufflen; 787 int good_bytes = (result == 0 ? this_count : 0); 788 sector_t block_sectors = 1; 789 u64 first_err_block; 790 sector_t error_sector; 791 struct scsi_sense_hdr sshdr; 792 int sense_valid = 0; 793 int sense_deferred = 0; 794 int info_valid; 795 796 if (result) { 797 sense_valid = scsi_command_normalize_sense(SCpnt, &sshdr); 798 if (sense_valid) 799 sense_deferred = scsi_sense_is_deferred(&sshdr); 800 } 801 802#ifdef CONFIG_SCSI_LOGGING 803 SCSI_LOG_HLCOMPLETE(1, printk("sd_rw_intr: %s: res=0x%x\n", 804 SCpnt->request->rq_disk->disk_name, result)); 805 if (sense_valid) { 806 SCSI_LOG_HLCOMPLETE(1, printk("sd_rw_intr: sb[respc,sk,asc," 807 "ascq]=%x,%x,%x,%x\n", sshdr.response_code, 808 sshdr.sense_key, sshdr.asc, sshdr.ascq)); 809 } 810#endif 811 /* 812 Handle MEDIUM ERRORs that indicate partial success. Since this is a 813 relatively rare error condition, no care is taken to avoid 814 unnecessary additional work such as memcpy's that could be avoided. 815 */ 816 if (driver_byte(result) != 0 && 817 sense_valid && !sense_deferred) { 818 switch (sshdr.sense_key) { 819 case MEDIUM_ERROR: 820 if (!blk_fs_request(SCpnt->request)) 821 break; 822 info_valid = scsi_get_sense_info_fld( 823 SCpnt->sense_buffer, SCSI_SENSE_BUFFERSIZE, 824 &first_err_block); 825 /* 826 * May want to warn and skip if following cast results 827 * in actual truncation (if sector_t < 64 bits) 828 */ 829 error_sector = (sector_t)first_err_block; 830 if (SCpnt->request->bio != NULL) 831 block_sectors = bio_sectors(SCpnt->request->bio); 832 switch (SCpnt->device->sector_size) { 833 case 1024: 834 error_sector <<= 1; 835 if (block_sectors < 2) 836 block_sectors = 2; 837 break; 838 case 2048: 839 error_sector <<= 2; 840 if (block_sectors < 4) 841 block_sectors = 4; 842 break; 843 case 4096: 844 error_sector <<=3; 845 if (block_sectors < 8) 846 block_sectors = 8; 847 break; 848 case 256: 849 error_sector >>= 1; 850 break; 851 default: 852 break; 853 } 854 855 error_sector &= ~(block_sectors - 1); 856 good_bytes = (error_sector - SCpnt->request->sector) << 9; 857 if (good_bytes < 0 || good_bytes >= this_count) 858 good_bytes = 0; 859 break; 860 861 case RECOVERED_ERROR: /* an error occurred, but it recovered */ 862 case NO_SENSE: /* LLDD got sense data */ 863 /* 864 * Inform the user, but make sure that it's not treated 865 * as a hard error. 866 */ 867 scsi_print_sense("sd", SCpnt); 868 SCpnt->result = 0; 869 memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); 870 good_bytes = this_count; 871 break; 872 873 case ILLEGAL_REQUEST: 874 if (SCpnt->device->use_10_for_rw && 875 (SCpnt->cmnd[0] == READ_10 || 876 SCpnt->cmnd[0] == WRITE_10)) 877 SCpnt->device->use_10_for_rw = 0; 878 if (SCpnt->device->use_10_for_ms && 879 (SCpnt->cmnd[0] == MODE_SENSE_10 || 880 SCpnt->cmnd[0] == MODE_SELECT_10)) 881 SCpnt->device->use_10_for_ms = 0; 882 break; 883 884 default: 885 break; 886 } 887 } 888 /* 889 * This calls the generic completion function, now that we know 890 * how many actual sectors finished, and how many sectors we need 891 * to say have failed. 892 */ 893 scsi_io_completion(SCpnt, good_bytes, block_sectors << 9); 894} 895 896static int media_not_present(struct scsi_disk *sdkp, 897 struct scsi_sense_hdr *sshdr) 898{ 899 900 if (!scsi_sense_valid(sshdr)) 901 return 0; 902 /* not invoked for commands that could return deferred errors */ 903 if (sshdr->sense_key != NOT_READY && 904 sshdr->sense_key != UNIT_ATTENTION) 905 return 0; 906 if (sshdr->asc != 0x3A) /* medium not present */ 907 return 0; 908 909 set_media_not_present(sdkp); 910 return 1; 911} 912 913/* 914 * spinup disk - called only in sd_revalidate_disk() 915 */ 916static void 917sd_spinup_disk(struct scsi_disk *sdkp, char *diskname) 918{ 919 unsigned char cmd[10]; 920 unsigned long spintime_expire = 0; 921 int retries, spintime; 922 unsigned int the_result; 923 struct scsi_sense_hdr sshdr; 924 int sense_valid = 0; 925 926 spintime = 0; 927 928 /* Spin up drives, as required. Only do this at boot time */ 929 /* Spinup needs to be done for module loads too. */ 930 do { 931 retries = 0; 932 933 do { 934 cmd[0] = TEST_UNIT_READY; 935 memset((void *) &cmd[1], 0, 9); 936 937 the_result = scsi_execute_req(sdkp->device, cmd, 938 DMA_NONE, NULL, 0, 939 &sshdr, SD_TIMEOUT, 940 SD_MAX_RETRIES); 941 942 if (the_result) 943 sense_valid = scsi_sense_valid(&sshdr); 944 retries++; 945 } while (retries < 3 && 946 (!scsi_status_is_good(the_result) || 947 ((driver_byte(the_result) & DRIVER_SENSE) && 948 sense_valid && sshdr.sense_key == UNIT_ATTENTION))); 949 950 /* 951 * If the drive has indicated to us that it doesn't have 952 * any media in it, don't bother with any of the rest of 953 * this crap. 954 */ 955 if (media_not_present(sdkp, &sshdr)) 956 return; 957 958 if ((driver_byte(the_result) & DRIVER_SENSE) == 0) { 959 /* no sense, TUR either succeeded or failed 960 * with a status error */ 961 if(!spintime && !scsi_status_is_good(the_result)) 962 printk(KERN_NOTICE "%s: Unit Not Ready, " 963 "error = 0x%x\n", diskname, the_result); 964 break; 965 } 966 967 /* 968 * The device does not want the automatic start to be issued. 969 */ 970 if (sdkp->device->no_start_on_add) { 971 break; 972 } 973 974 /* 975 * If manual intervention is required, or this is an 976 * absent USB storage device, a spinup is meaningless. 977 */ 978 if (sense_valid && 979 sshdr.sense_key == NOT_READY && 980 sshdr.asc == 4 && sshdr.ascq == 3) { 981 break; /* manual intervention required */ 982 983 /* 984 * Issue command to spin up drive when not ready 985 */ 986 } else if (sense_valid && sshdr.sense_key == NOT_READY) { 987 if (!spintime) { 988 printk(KERN_NOTICE "%s: Spinning up disk...", 989 diskname); 990 cmd[0] = START_STOP; 991 cmd[1] = 1; /* Return immediately */ 992 memset((void *) &cmd[2], 0, 8); 993 cmd[4] = 1; /* Start spin cycle */ 994 scsi_execute_req(sdkp->device, cmd, DMA_NONE, 995 NULL, 0, &sshdr, 996 SD_TIMEOUT, SD_MAX_RETRIES); 997 spintime_expire = jiffies + 100 * HZ; 998 spintime = 1; 999 } 1000 /* Wait 1 second for next try */ 1001 msleep(1000); 1002 printk("."); 1003 1004 /* 1005 * Wait for USB flash devices with slow firmware. 1006 * Yes, this sense key/ASC combination shouldn't 1007 * occur here. It's characteristic of these devices. 1008 */ 1009 } else if (sense_valid && 1010 sshdr.sense_key == UNIT_ATTENTION && 1011 sshdr.asc == 0x28) { 1012 if (!spintime) { 1013 spintime_expire = jiffies + 5 * HZ; 1014 spintime = 1; 1015 } 1016 /* Wait 1 second for next try */ 1017 msleep(1000); 1018 } else { 1019 /* we don't understand the sense code, so it's 1020 * probably pointless to loop */ 1021 if(!spintime) { 1022 printk(KERN_NOTICE "%s: Unit Not Ready, " 1023 "sense:\n", diskname); 1024 scsi_print_sense_hdr("", &sshdr); 1025 } 1026 break; 1027 } 1028 1029 } while (spintime && time_before_eq(jiffies, spintime_expire)); 1030 1031 if (spintime) { 1032 if (scsi_status_is_good(the_result)) 1033 printk("ready\n"); 1034 else 1035 printk("not responding...\n"); 1036 } 1037} 1038 1039/* 1040 * read disk capacity 1041 */ 1042static void 1043sd_read_capacity(struct scsi_disk *sdkp, char *diskname, 1044 unsigned char *buffer) 1045{ 1046 unsigned char cmd[16]; 1047 int the_result, retries; 1048 int sector_size = 0; 1049 int longrc = 0; 1050 struct scsi_sense_hdr sshdr; 1051 int sense_valid = 0; 1052 struct scsi_device *sdp = sdkp->device; 1053 1054repeat: 1055 retries = 3; 1056 do { 1057 if (longrc) { 1058 memset((void *) cmd, 0, 16); 1059 cmd[0] = SERVICE_ACTION_IN; 1060 cmd[1] = SAI_READ_CAPACITY_16; 1061 cmd[13] = 12; 1062 memset((void *) buffer, 0, 12); 1063 } else { 1064 cmd[0] = READ_CAPACITY; 1065 memset((void *) &cmd[1], 0, 9); 1066 memset((void *) buffer, 0, 8); 1067 } 1068 1069 the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE, 1070 buffer, longrc ? 12 : 8, &sshdr, 1071 SD_TIMEOUT, SD_MAX_RETRIES); 1072 1073 if (media_not_present(sdkp, &sshdr)) 1074 return; 1075 1076 if (the_result) 1077 sense_valid = scsi_sense_valid(&sshdr); 1078 retries--; 1079 1080 } while (the_result && retries); 1081 1082 if (the_result && !longrc) { 1083 printk(KERN_NOTICE "%s : READ CAPACITY failed.\n" 1084 "%s : status=%x, message=%02x, host=%d, driver=%02x \n", 1085 diskname, diskname, 1086 status_byte(the_result), 1087 msg_byte(the_result), 1088 host_byte(the_result), 1089 driver_byte(the_result)); 1090 1091 if (driver_byte(the_result) & DRIVER_SENSE) 1092 scsi_print_sense_hdr("sd", &sshdr); 1093 else 1094 printk("%s : sense not available. \n", diskname); 1095 1096 /* Set dirty bit for removable devices if not ready - 1097 * sometimes drives will not report this properly. */ 1098 if (sdp->removable && 1099 sense_valid && sshdr.sense_key == NOT_READY) 1100 sdp->changed = 1; 1101 1102 /* Either no media are present but the drive didn't tell us, 1103 or they are present but the read capacity command fails */ 1104 /* sdkp->media_present = 0; -- not always correct */ 1105 sdkp->capacity = 0x200000; /* 1 GB - random */ 1106 1107 return; 1108 } else if (the_result && longrc) { 1109 /* READ CAPACITY(16) has been failed */ 1110 printk(KERN_NOTICE "%s : READ CAPACITY(16) failed.\n" 1111 "%s : status=%x, message=%02x, host=%d, driver=%02x \n", 1112 diskname, diskname, 1113 status_byte(the_result), 1114 msg_byte(the_result), 1115 host_byte(the_result), 1116 driver_byte(the_result)); 1117 printk(KERN_NOTICE "%s : use 0xffffffff as device size\n", 1118 diskname); 1119 1120 sdkp->capacity = 1 + (sector_t) 0xffffffff; 1121 goto got_data; 1122 } 1123 1124 if (!longrc) { 1125 sector_size = (buffer[4] << 24) | 1126 (buffer[5] << 16) | (buffer[6] << 8) | buffer[7]; 1127 if (buffer[0] == 0xff && buffer[1] == 0xff && 1128 buffer[2] == 0xff && buffer[3] == 0xff) { 1129 if(sizeof(sdkp->capacity) > 4) { 1130 printk(KERN_NOTICE "%s : very big device. try to use" 1131 " READ CAPACITY(16).\n", diskname); 1132 longrc = 1; 1133 goto repeat; 1134 } 1135 printk(KERN_ERR "%s: too big for this kernel. Use a " 1136 "kernel compiled with support for large block " 1137 "devices.\n", diskname); 1138 sdkp->capacity = 0; 1139 goto got_data; 1140 } 1141 sdkp->capacity = 1 + (((sector_t)buffer[0] << 24) | 1142 (buffer[1] << 16) | 1143 (buffer[2] << 8) | 1144 buffer[3]); 1145 } else { 1146 sdkp->capacity = 1 + (((u64)buffer[0] << 56) | 1147 ((u64)buffer[1] << 48) | 1148 ((u64)buffer[2] << 40) | 1149 ((u64)buffer[3] << 32) | 1150 ((sector_t)buffer[4] << 24) | 1151 ((sector_t)buffer[5] << 16) | 1152 ((sector_t)buffer[6] << 8) | 1153 (sector_t)buffer[7]); 1154 1155 sector_size = (buffer[8] << 24) | 1156 (buffer[9] << 16) | (buffer[10] << 8) | buffer[11]; 1157 } 1158 1159 /* Some devices return the total number of sectors, not the 1160 * highest sector number. Make the necessary adjustment. */ 1161 if (sdp->fix_capacity) 1162 --sdkp->capacity; 1163 1164got_data: 1165 if (sector_size == 0) { 1166 sector_size = 512; 1167 printk(KERN_NOTICE "%s : sector size 0 reported, " 1168 "assuming 512.\n", diskname); 1169 } 1170 1171 if (sector_size != 512 && 1172 sector_size != 1024 && 1173 sector_size != 2048 && 1174 sector_size != 4096 && 1175 sector_size != 256) { 1176 printk(KERN_NOTICE "%s : unsupported sector size " 1177 "%d.\n", diskname, sector_size); 1178 /* 1179 * The user might want to re-format the drive with 1180 * a supported sectorsize. Once this happens, it 1181 * would be relatively trivial to set the thing up. 1182 * For this reason, we leave the thing in the table. 1183 */ 1184 sdkp->capacity = 0; 1185 /* 1186 * set a bogus sector size so the normal read/write 1187 * logic in the block layer will eventually refuse any 1188 * request on this device without tripping over power 1189 * of two sector size assumptions 1190 */ 1191 sector_size = 512; 1192 } 1193 { 1194 /* 1195 * The msdos fs needs to know the hardware sector size 1196 * So I have created this table. See ll_rw_blk.c 1197 * Jacques Gelinas (Jacques@solucorp.qc.ca) 1198 */ 1199 int hard_sector = sector_size; 1200 sector_t sz = (sdkp->capacity/2) * (hard_sector/256); 1201 request_queue_t *queue = sdp->request_queue; 1202 sector_t mb = sz; 1203 1204 blk_queue_hardsect_size(queue, hard_sector); 1205 /* avoid 64-bit division on 32-bit platforms */ 1206 sector_div(sz, 625); 1207 mb -= sz - 974; 1208 sector_div(mb, 1950); 1209 1210 printk(KERN_NOTICE "SCSI device %s: " 1211 "%llu %d-byte hdwr sectors (%llu MB)\n", 1212 diskname, (unsigned long long)sdkp->capacity, 1213 hard_sector, (unsigned long long)mb); 1214 } 1215 1216 /* Rescale capacity to 512-byte units */ 1217 if (sector_size == 4096) 1218 sdkp->capacity <<= 3; 1219 else if (sector_size == 2048) 1220 sdkp->capacity <<= 2; 1221 else if (sector_size == 1024) 1222 sdkp->capacity <<= 1; 1223 else if (sector_size == 256) 1224 sdkp->capacity >>= 1; 1225 1226 sdkp->device->sector_size = sector_size; 1227} 1228 1229/* called with buffer of length 512 */ 1230static inline int 1231sd_do_mode_sense(struct scsi_device *sdp, int dbd, int modepage, 1232 unsigned char *buffer, int len, struct scsi_mode_data *data, 1233 struct scsi_sense_hdr *sshdr) 1234{ 1235 return scsi_mode_sense(sdp, dbd, modepage, buffer, len, 1236 SD_TIMEOUT, SD_MAX_RETRIES, data, 1237 sshdr); 1238} 1239 1240/* 1241 * read write protect setting, if possible - called only in sd_revalidate_disk() 1242 * called with buffer of length 512 1243 */ 1244static void 1245sd_read_write_protect_flag(struct scsi_disk *sdkp, char *diskname, 1246 unsigned char *buffer) 1247{ 1248 int res; 1249 struct scsi_device *sdp = sdkp->device; 1250 struct scsi_mode_data data; 1251 1252 set_disk_ro(sdkp->disk, 0); 1253 if (sdp->skip_ms_page_3f) { 1254 printk(KERN_NOTICE "%s: assuming Write Enabled\n", diskname); 1255 return; 1256 } 1257 1258 if (sdp->use_192_bytes_for_3f) { 1259 res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 192, &data, NULL); 1260 } else { 1261 /* 1262 * First attempt: ask for all pages (0x3F), but only 4 bytes. 1263 * We have to start carefully: some devices hang if we ask 1264 * for more than is available. 1265 */ 1266 res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 4, &data, NULL); 1267 1268 /* 1269 * Second attempt: ask for page 0 When only page 0 is 1270 * implemented, a request for page 3F may return Sense Key 1271 * 5: Illegal Request, Sense Code 24: Invalid field in 1272 * CDB. 1273 */ 1274 if (!scsi_status_is_good(res)) 1275 res = sd_do_mode_sense(sdp, 0, 0, buffer, 4, &data, NULL); 1276 1277 /* 1278 * Third attempt: ask 255 bytes, as we did earlier. 1279 */ 1280 if (!scsi_status_is_good(res)) 1281 res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 255, 1282 &data, NULL); 1283 } 1284 1285 if (!scsi_status_is_good(res)) { 1286 printk(KERN_WARNING 1287 "%s: test WP failed, assume Write Enabled\n", diskname); 1288 } else { 1289 sdkp->write_prot = ((data.device_specific & 0x80) != 0); 1290 set_disk_ro(sdkp->disk, sdkp->write_prot); 1291 printk(KERN_NOTICE "%s: Write Protect is %s\n", diskname, 1292 sdkp->write_prot ? "on" : "off"); 1293 printk(KERN_DEBUG "%s: Mode Sense: %02x %02x %02x %02x\n", 1294 diskname, buffer[0], buffer[1], buffer[2], buffer[3]); 1295 } 1296} 1297 1298/* 1299 * sd_read_cache_type - called only from sd_revalidate_disk() 1300 * called with buffer of length 512 1301 */ 1302static void 1303sd_read_cache_type(struct scsi_disk *sdkp, char *diskname, 1304 unsigned char *buffer) 1305{ 1306 int len = 0, res; 1307 struct scsi_device *sdp = sdkp->device; 1308 1309 int dbd; 1310 int modepage; 1311 struct scsi_mode_data data; 1312 struct scsi_sense_hdr sshdr; 1313 1314 if (sdp->skip_ms_page_8) 1315 goto defaults; 1316 1317 if (sdp->type == TYPE_RBC) { 1318 modepage = 6; 1319 dbd = 8; 1320 } else { 1321 modepage = 8; 1322 dbd = 0; 1323 } 1324 1325 /* cautiously ask */ 1326 res = sd_do_mode_sense(sdp, dbd, modepage, buffer, 4, &data, &sshdr); 1327 1328 if (!scsi_status_is_good(res)) 1329 goto bad_sense; 1330 1331 /* that went OK, now ask for the proper length */ 1332 len = data.length; 1333 1334 /* 1335 * We're only interested in the first three bytes, actually. 1336 * But the data cache page is defined for the first 20. 1337 */ 1338 if (len < 3) 1339 goto bad_sense; 1340 if (len > 20) 1341 len = 20; 1342 1343 /* Take headers and block descriptors into account */ 1344 len += data.header_length + data.block_descriptor_length; 1345 1346 /* Get the data */ 1347 res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len, &data, &sshdr); 1348 1349 if (scsi_status_is_good(res)) { 1350 const char *types[] = { 1351 "write through", "none", "write back", 1352 "write back, no read (daft)" 1353 }; 1354 int ct = 0; 1355 int offset = data.header_length + data.block_descriptor_length; 1356 1357 if ((buffer[offset] & 0x3f) != modepage) { 1358 printk(KERN_ERR "%s: got wrong page\n", diskname); 1359 goto defaults; 1360 } 1361 1362 if (modepage == 8) { 1363 sdkp->WCE = ((buffer[offset + 2] & 0x04) != 0); 1364 sdkp->RCD = ((buffer[offset + 2] & 0x01) != 0); 1365 } else { 1366 sdkp->WCE = ((buffer[offset + 2] & 0x01) == 0); 1367 sdkp->RCD = 0; 1368 } 1369 1370 sdkp->DPOFUA = (data.device_specific & 0x10) != 0; 1371 if (sdkp->DPOFUA && !sdkp->device->use_10_for_rw) { 1372 printk(KERN_NOTICE "SCSI device %s: uses " 1373 "READ/WRITE(6), disabling FUA\n", diskname); 1374 sdkp->DPOFUA = 0; 1375 } 1376 1377 ct = sdkp->RCD + 2*sdkp->WCE; 1378 1379 printk(KERN_NOTICE "SCSI device %s: drive cache: %s%s\n", 1380 diskname, types[ct], 1381 sdkp->DPOFUA ? " w/ FUA" : ""); 1382 1383 return; 1384 } 1385 1386bad_sense: 1387 if (scsi_sense_valid(&sshdr) && 1388 sshdr.sense_key == ILLEGAL_REQUEST && 1389 sshdr.asc == 0x24 && sshdr.ascq == 0x0) 1390 printk(KERN_NOTICE "%s: cache data unavailable\n", 1391 diskname); /* Invalid field in CDB */ 1392 else 1393 printk(KERN_ERR "%s: asking for cache data failed\n", 1394 diskname); 1395 1396defaults: 1397 printk(KERN_ERR "%s: assuming drive cache: write through\n", 1398 diskname); 1399 sdkp->WCE = 0; 1400 sdkp->RCD = 0; 1401} 1402 1403/** 1404 * sd_revalidate_disk - called the first time a new disk is seen, 1405 * performs disk spin up, read_capacity, etc. 1406 * @disk: struct gendisk we care about 1407 **/ 1408static int sd_revalidate_disk(struct gendisk *disk) 1409{ 1410 struct scsi_disk *sdkp = scsi_disk(disk); 1411 struct scsi_device *sdp = sdkp->device; 1412 unsigned char *buffer; 1413 unsigned ordered; 1414 1415 SCSI_LOG_HLQUEUE(3, printk("sd_revalidate_disk: disk=%s\n", disk->disk_name)); 1416 1417 /* 1418 * If the device is offline, don't try and read capacity or any 1419 * of the other niceties. 1420 */ 1421 if (!scsi_device_online(sdp)) 1422 goto out; 1423 1424 buffer = kmalloc(512, GFP_KERNEL | __GFP_DMA); 1425 if (!buffer) { 1426 printk(KERN_WARNING "(sd_revalidate_disk:) Memory allocation " 1427 "failure.\n"); 1428 goto out; 1429 } 1430 1431 /* defaults, until the device tells us otherwise */ 1432 sdp->sector_size = 512; 1433 sdkp->capacity = 0; 1434 sdkp->media_present = 1; 1435 sdkp->write_prot = 0; 1436 sdkp->WCE = 0; 1437 sdkp->RCD = 0; 1438 1439 sd_spinup_disk(sdkp, disk->disk_name); 1440 1441 /* 1442 * Without media there is no reason to ask; moreover, some devices 1443 * react badly if we do. 1444 */ 1445 if (sdkp->media_present) { 1446 sd_read_capacity(sdkp, disk->disk_name, buffer); 1447 sd_read_write_protect_flag(sdkp, disk->disk_name, buffer); 1448 sd_read_cache_type(sdkp, disk->disk_name, buffer); 1449 } 1450 1451 /* 1452 * We now have all cache related info, determine how we deal 1453 * with ordered requests. Note that as the current SCSI 1454 * dispatch function can alter request order, we cannot use 1455 * QUEUE_ORDERED_TAG_* even when ordered tag is supported. 1456 */ 1457 if (sdkp->WCE) 1458 ordered = sdkp->DPOFUA 1459 ? QUEUE_ORDERED_DRAIN_FUA : QUEUE_ORDERED_DRAIN_FLUSH; 1460 else 1461 ordered = QUEUE_ORDERED_DRAIN; 1462 1463 blk_queue_ordered(sdkp->disk->queue, ordered, sd_prepare_flush); 1464 1465 set_capacity(disk, sdkp->capacity); 1466 kfree(buffer); 1467 1468 out: 1469 return 0; 1470} 1471 1472/** 1473 * sd_probe - called during driver initialization and whenever a 1474 * new scsi device is attached to the system. It is called once 1475 * for each scsi device (not just disks) present. 1476 * @dev: pointer to device object 1477 * 1478 * Returns 0 if successful (or not interested in this scsi device 1479 * (e.g. scanner)); 1 when there is an error. 1480 * 1481 * Note: this function is invoked from the scsi mid-level. 1482 * This function sets up the mapping between a given 1483 * <host,channel,id,lun> (found in sdp) and new device name 1484 * (e.g. /dev/sda). More precisely it is the block device major 1485 * and minor number that is chosen here. 1486 * 1487 * Assume sd_attach is not re-entrant (for time being) 1488 * Also think about sd_attach() and sd_remove() running coincidentally. 1489 **/ 1490static int sd_probe(struct device *dev) 1491{ 1492 struct scsi_device *sdp = to_scsi_device(dev); 1493 struct scsi_disk *sdkp; 1494 struct gendisk *gd; 1495 u32 index; 1496 int error; 1497 1498 error = -ENODEV; 1499 if (sdp->type != TYPE_DISK && sdp->type != TYPE_MOD && sdp->type != TYPE_RBC) 1500 goto out; 1501 1502 SCSI_LOG_HLQUEUE(3, sdev_printk(KERN_INFO, sdp, 1503 "sd_attach\n")); 1504 1505 error = -ENOMEM; 1506 sdkp = kmalloc(sizeof(*sdkp), GFP_KERNEL); 1507 if (!sdkp) 1508 goto out; 1509 1510 memset (sdkp, 0, sizeof(*sdkp)); 1511 kref_init(&sdkp->kref); 1512 1513 gd = alloc_disk(16); 1514 if (!gd) 1515 goto out_free; 1516 1517 if (!idr_pre_get(&sd_index_idr, GFP_KERNEL)) 1518 goto out_put; 1519 1520 spin_lock(&sd_index_lock); 1521 error = idr_get_new(&sd_index_idr, NULL, &index); 1522 spin_unlock(&sd_index_lock); 1523 1524 if (index >= SD_MAX_DISKS) 1525 error = -EBUSY; 1526 if (error) 1527 goto out_put; 1528 1529 get_device(&sdp->sdev_gendev); 1530 sdkp->device = sdp; 1531 sdkp->driver = &sd_template; 1532 sdkp->disk = gd; 1533 sdkp->index = index; 1534 sdkp->openers = 0; 1535 1536 if (!sdp->timeout) { 1537 if (sdp->type != TYPE_MOD) 1538 sdp->timeout = SD_TIMEOUT; 1539 else 1540 sdp->timeout = SD_MOD_TIMEOUT; 1541 } 1542 1543 gd->major = sd_major((index & 0xf0) >> 4); 1544 gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00); 1545 gd->minors = 16; 1546 gd->fops = &sd_fops; 1547 1548 if (index < 26) { 1549 sprintf(gd->disk_name, "sd%c", 'a' + index % 26); 1550 } else if (index < (26 + 1) * 26) { 1551 sprintf(gd->disk_name, "sd%c%c", 1552 'a' + index / 26 - 1,'a' + index % 26); 1553 } else { 1554 const unsigned int m1 = (index / 26 - 1) / 26 - 1; 1555 const unsigned int m2 = (index / 26 - 1) % 26; 1556 const unsigned int m3 = index % 26; 1557 sprintf(gd->disk_name, "sd%c%c%c", 1558 'a' + m1, 'a' + m2, 'a' + m3); 1559 } 1560 1561 strcpy(gd->devfs_name, sdp->devfs_name); 1562 1563 gd->private_data = &sdkp->driver; 1564 gd->queue = sdkp->device->request_queue; 1565 1566 sd_revalidate_disk(gd); 1567 1568 gd->driverfs_dev = &sdp->sdev_gendev; 1569 gd->flags = GENHD_FL_DRIVERFS; 1570 if (sdp->removable) 1571 gd->flags |= GENHD_FL_REMOVABLE; 1572 1573 dev_set_drvdata(dev, sdkp); 1574 add_disk(gd); 1575 1576 sdev_printk(KERN_NOTICE, sdp, "Attached scsi %sdisk %s\n", 1577 sdp->removable ? "removable " : "", gd->disk_name); 1578 1579 return 0; 1580 1581out_put: 1582 put_disk(gd); 1583out_free: 1584 kfree(sdkp); 1585out: 1586 return error; 1587} 1588 1589/** 1590 * sd_remove - called whenever a scsi disk (previously recognized by 1591 * sd_probe) is detached from the system. It is called (potentially 1592 * multiple times) during sd module unload. 1593 * @sdp: pointer to mid level scsi device object 1594 * 1595 * Note: this function is invoked from the scsi mid-level. 1596 * This function potentially frees up a device name (e.g. /dev/sdc) 1597 * that could be re-used by a subsequent sd_probe(). 1598 * This function is not called when the built-in sd driver is "exit-ed". 1599 **/ 1600static int sd_remove(struct device *dev) 1601{ 1602 struct scsi_disk *sdkp = dev_get_drvdata(dev); 1603 1604 del_gendisk(sdkp->disk); 1605 sd_shutdown(dev); 1606 1607 mutex_lock(&sd_ref_mutex); 1608 dev_set_drvdata(dev, NULL); 1609 kref_put(&sdkp->kref, scsi_disk_release); 1610 mutex_unlock(&sd_ref_mutex); 1611 1612 return 0; 1613} 1614 1615/** 1616 * scsi_disk_release - Called to free the scsi_disk structure 1617 * @kref: pointer to embedded kref 1618 * 1619 * sd_ref_mutex must be held entering this routine. Because it is 1620 * called on last put, you should always use the scsi_disk_get() 1621 * scsi_disk_put() helpers which manipulate the semaphore directly 1622 * and never do a direct kref_put(). 1623 **/ 1624static void scsi_disk_release(struct kref *kref) 1625{ 1626 struct scsi_disk *sdkp = to_scsi_disk(kref); 1627 struct gendisk *disk = sdkp->disk; 1628 1629 spin_lock(&sd_index_lock); 1630 idr_remove(&sd_index_idr, sdkp->index); 1631 spin_unlock(&sd_index_lock); 1632 1633 disk->private_data = NULL; 1634 put_disk(disk); 1635 put_device(&sdkp->device->sdev_gendev); 1636 1637 kfree(sdkp); 1638} 1639 1640/* 1641 * Send a SYNCHRONIZE CACHE instruction down to the device through 1642 * the normal SCSI command structure. Wait for the command to 1643 * complete. 1644 */ 1645static void sd_shutdown(struct device *dev) 1646{ 1647 struct scsi_device *sdp = to_scsi_device(dev); 1648 struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev); 1649 1650 if (!sdkp) 1651 return; /* this can happen */ 1652 1653 if (sdkp->WCE) { 1654 printk(KERN_NOTICE "Synchronizing SCSI cache for disk %s: \n", 1655 sdkp->disk->disk_name); 1656 sd_sync_cache(sdp); 1657 } 1658 scsi_disk_put(sdkp); 1659} 1660 1661/** 1662 * init_sd - entry point for this driver (both when built in or when 1663 * a module). 1664 * 1665 * Note: this function registers this driver with the scsi mid-level. 1666 **/ 1667static int __init init_sd(void) 1668{ 1669 int majors = 0, i; 1670 1671 SCSI_LOG_HLQUEUE(3, printk("init_sd: sd driver entry point\n")); 1672 1673 for (i = 0; i < SD_MAJORS; i++) 1674 if (register_blkdev(sd_major(i), "sd") == 0) 1675 majors++; 1676 1677 if (!majors) 1678 return -ENODEV; 1679 1680 return scsi_register_driver(&sd_template.gendrv); 1681} 1682 1683/** 1684 * exit_sd - exit point for this driver (when it is a module). 1685 * 1686 * Note: this function unregisters this driver from the scsi mid-level. 1687 **/ 1688static void __exit exit_sd(void) 1689{ 1690 int i; 1691 1692 SCSI_LOG_HLQUEUE(3, printk("exit_sd: exiting sd driver\n")); 1693 1694 scsi_unregister_driver(&sd_template.gendrv); 1695 for (i = 0; i < SD_MAJORS; i++) 1696 unregister_blkdev(sd_major(i), "sd"); 1697} 1698 1699MODULE_LICENSE("GPL"); 1700MODULE_AUTHOR("Eric Youngdale"); 1701MODULE_DESCRIPTION("SCSI disk (sd) driver"); 1702 1703module_init(init_sd); 1704module_exit(exit_sd); 1705